The special counsel also buried once and for all Donald Trump’s mealy-mouthed obfuscations over whether Russia was responsible for this confidence trick of breathtaking scope and scale. Former CIA director-general Michael Hayden has described it as the political equivalent of the September 11 terrorist attacks.

But what Mueller has not yet produced is compelling evidence that demonstrates the president or his campaign knowingly coordinated with Russians to cheat Hillary Clinton out of the election.

Trump, predictably, claimed vindication. “Russia started their anti-US campaign in 2014, long before I announced that I would run for president,” he tweeted on Friday as he departed the White House for Florida. “The results of the election were not impacted. The Trump campaign did nothing wrong – no collusion!”

In addition, an ad shortly before the election promoted the Green party candidate Jill Stein, who proved crucial in splitting the Clinton vote in the decisive states of Pennsylvania, Michigan and Wisconsin. Russians posing as Trump supporters, and as anti-Trump groups such as Black Lives Matter, organised campaign events.

Clinton’s supporters will seize on the charge that there was a deliberate attempt to undermine their candidate. But Trump loyalists will be quick to point out that Sanders and Stein were also intended to benefit. That would appear to support the theory that the meddling was more about Vladimir Putin’s personal animosity towards Clinton, or about stirring chaos in general, than anything else.

The charges say that Russians also communicated with “unwitting individuals” associated with the Trump campaign and other political activists to coordinate activities. There is succour for Trump in that word “unwitting”.

Ten key takeaways from Mueller's Russia indictment

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And in a televised press conference that may have been to Trump’s benefit, Rod Rosenstein, the deputy attorney general, was at pains to say the 37-page indictment does not allege that anyone on the Trump campaign was aware of or involved in the Russian effort, nor that the outcome of the election was affected – the latter claim being surely impossible for anyone to know.

Ari Fleischer, former White House press secretary, tweeted: “The report knocks the legs out from the Democrats’ most serious charge – that Trump colluded. If there was collusion, it would have been made known today.”

But this is hardly the end of the matter. Before Friday, four people, including Trump’s former national security adviser and former campaign chairman, had been charged. Steve Bannon, former White House chief strategist, was interviewed for 20 hours this week. It remains to be seen if Trump himself will be questioned.

As Adam Schiff, ranking member of the House intelligence committee, noted on Friday, the indictment “leaves open” the question of whether Americans – including any involved in the Trump campaign – deliberately played a role in Russia’s industrial-scale election meddling.